Process and apparatus for cracking hydrocarbon oils



June 28, 1932- c, COOK 1,865,172

PROCESS AND APPARATUS FOR CRACKING HYDROCARBON OILS Filed Jan. 9, 1928Patented June 28, 1932 UNITED STATES PATENT OFFICE RALPH C. COOK, OFCHICAGO, ILLINOIS, ASSIGNOR TO UNIVERSAL OIL PRODUCTS COM- PANY, OFCHICAGO, ILLINOIS, A CORPORATION OF SOUTH DAKOTA PROCESS AND APPARATUSFOR CRACKING HYDROCARIBON OILS Application filed January 9, 1928. SerialNo. 245,387.

I11 the cracking of hydrocarbon oils, as for example, in the well knowntype of heat and pressure process in which the oil may be fed through asuitable heating coil thence to an enlarged expansion chamber and thevapor removed from said chamber and subjected to dephlegmation,difliculty has been experi enced in obtaining satisfactory separation ofthe sufliciently cracked from the insufliciently cracked vapors. Invarious types of packed towers or dephlegmators, there has been, in manycases, a pronounced tendency for the vapors to channel, thus preventingproper fractionation. Also in these types of dephlegmators, difiicultyis frequently experienced in entrainment. The object of the invention isto prevent suchchanneling and entrainment, and to accomplish it in apractical manner which can be utilized by an oil refiner.

Inasmuch asthe type of apparatus in which these dephlegmators are usedis well known,- it will not be necessary to show them in drawing, butonly to show the type of dephlegmator utilized in such process andapparatus. In the drawing, Fig. 1 is a vertical sectional view of thedephleginator used in my apparatus and process. Fig. 2 is a fragmentary,horizontal, sectional View of the same.

In carrying out the process, the oil may be passed through a suitableheating coil, where it may be heated to a transfer temperature of 800F., or more, and thence passed to the usual expansion chamber. Herevaporization takes place, the residue may be drawn off and the vaporspassed to the dephlegmator. The temperature of the dephlegmator may besuitably controlled so that only the gasolene constituents, for example,will remain uncondensed and will pass out through the invention, thedephlegmator may consist of an outer cylindrical shell 1, divided bymeans of perforated plates 2 forming a plurality of superimposedcompartments 3. Between the plates 2 are mounted a series of nestedvapor pipes, or conduits 4, which I have shown as hexagonal in crosssection, but they may be of any desired cross section contour. Thelowermost plate 5 is supported on suitable lugs or brackets 6, and thesuperimposed plates may rest on the top of corresponding internestedpipes 4.

Spaced away from the top of the uppermost pipes 4 is a plate of the wellknown bubble tray type 7, provided with risers 8 and spaced caps 9 andopen ended reflux return pipes 10. By means of the bubble trays 7 thecooling medium, which may be the raw oil, is uniformly distributed intothe pipes 4. The oil may be fed through the inlet line 11,

as shown. Each of the pipe sections 4 is preferably packed throughout aportion of its height with suitable packing 12, as for example, Raschigrings, or other suitable packing material. The reflux condensate iscollected in the bottom chamber 13,and thence is drawn out through thereflux return pipe 14. The vapors may enter the bottom of thedephlegmator through the vapor inlet pipe 15, the various pipes 11, 14and 15 being controlled by' suitable throttle valves.

As the vapors enter the lower end of the dephlegmator, they will passthrough the perforated plate 5, up through the adjacent set of thevertical conduits 4, through the packing up through the superimposedplates 2 and through the corresponding sets. of vapor pipes, as shown.It will be noted that the upper portion of the various pipes 4 do nothave any packing. This permits any liquid which is carried into suchopen space by the ascending vapors to drop out and flow back into thepacking. The-arrangement is such that in each compartment there isobtained a fractionation or separation of the lighter from the heavierfractions within relatively narrow limits.

It will also be noted that the relatively small cross section of eachpipe 4 in relation with the diameter of the cylindrical shell willprevent channeling of the vapors in their passage through thedephlegmator.

I claim as my invention- 1. A process of treating hydrocarbon oil vaporsto separate insufficiently cracked constituents from suflicientlycracked vapors, which consists in passing the vapors to be treatedupward in a plurality of parallel in dependent streams, causing thevapors in each of said streams to pass through packing material,subsequently causing the vapors to bubble through a pool of refluxingliquid, causing liquid from said pool to flow downwardly in contact withand countercurrent to the rising vapors, and thereafter withdrawing saidvapors for condensation as the product of the process.

2. A process of treating hydrocarbon oil vapors to separateinsufficiently cracked constituents from sufiiciently cracked vapors,which consists in passing the vapors to be treated to the lower portionof a treating zone, maintaining a pool of refluxing liquid at the upperportion thereof, causing the vapors to ascend and liquid from said poolto descend through packing material, subsequently causing the vapors tobubble through said pool of refluxing liquid, and thereafter withdrawingsaid vapors for condensation as the product of the process.

4 3. A process of treating hydrocarbon oil vapors to separate higherboiling point constituents from the vapors of lower boiling pointconstituents, which consists in introducing the vapors to be treated atthe lower portion of the treating zone, introducing a condensing liquidat the upper portion of the treating zone, maintaining a pool of saidliquid near the point of liquid introduction and causingthe ascendingvapors to bubble therethrough, dividing the vapors introduced at thelower portion of said zone into a plurality of upwardly directedindependent streams, causing the vapors in each stream to pass throughgranular packing material, conducting the overflow from said pool to aregion above said packing material and discharging it thereover topermit it to descend therethrough and pass over the surfaces of saidpacking material in contact with the ascending vapors, and withdrawingthe con densing liquid after contacting with the vapors, from the lowerportion of the treating zone.

4. A device for use in heat treating process for hydrocarbon oils inwhich oil vapors are evolved, comprising in combination,.a chamber,means for introducing heated oil vapors at the lower portion of saidchamber, means for introducing a condensing liquid at the upper portionthereof, vertical partitions dividin the intermediate portion of saidchamber into a plurality of vertical passages, I a transverse partitionfor supporting a quantity of packing material in each passage, saidpartitions being perforated to permit ascendlng vapors to pass throughsaid material, a transverse partition above said vertical partitionsadapted to retain a pool of condensing liquid, means for causing thevapors passing from said packing material to bubble through said 001 ofliquid, and means for collecting t e vapors after bubbling through saidpool for condensation as the'product of the process.

5. A dephlegmator comprising a shell, a vapor inlet adjacent the lowerportion of said shell and a vapor outlet adjacent the upper portionthereof, a perforated partition within said shell, a plurality ofvertical vapor conduits supported at their lower ends on said partition,means for retaining a pool of liquid in the upper portion of said shell,means for supplying liquid from said pool to said vapor conduits, andmeans for passing vapors from said conduits through said pool.

6. A dephlegmator comprising a shell, a vapor inlet adjacent the lowerportion of said shell and a vapor outlet adjacent the upper portionthereof, a perforated partition within said shell, a plurality ofvertical vapor conduits supported at their lower ends on said partition,and packing material in the lower portions of said conduits, means forretaining a pool of liquid in the upper portion of said shell, means forsupplying liquid from said pool to said vapor conduits, and means forpassing vapors from said conduits through said pool.

RALPH O. COOK.

